article: What are your clothes made of? Are they made of cotton or wool? Some students in Shandong wear different things. Their clothes are made of discs  or old clothes!
  On October 7th, 36 students in Linyi, Shandong Province, wore beautiful clothes in a show. Their clothes were made of all kinds of things.
  The show gave the students a chance to make things with their own hands. It also helped them learn to make good use of waste and not to throw everything away.
  Students had lots of good ideas. Some found used things, like old clothes, to make new dresses.
  "We hope to save energy. Our world is _ of energy. So I don't want to just throw old things away," said Xie Jing at Linyi Art School.
  Xie had more than 20 discs on her nice blue dress. She got them from her family and friends.
  "Though the discs are old, I look very cool in them!" she said.
  Song Dandan, a student from the school, looked like a farmer in her straw  coat and hat. She picked the straw from the fields and put them all together.
  "I want to show what people wore in the past." she said.
  Du Yue made clothes for astronauts ! She had white cloth all over her. When she walked, she tried to be slow. It looked like she was walking on the moon.
  "I hope to wear it in space  some day. I wish that I could walk on the moon!" she said.
question: The show tells people   _  .
options: we should save energy they are clever how to make use of old things A, B and C